Application of chemically modified waste tucumã (Astrocaryum aculeatum) seeds in the biosorption of methylene blue: kinetic and thermodynamic parameters.

Dye effluents cause diverse environmental problems. Methylene blue (MB) dye stands out since it is widely used in the textile industry. To reduce the pollution caused by the MB, we developed biosorbents from tucumã seeds, where the in natura seeds were treated with NaOH (BT) and H3PO4 (AT) solutions and characterized by Boehm titration, point of zero charges, FTIR, TGA, BET, and SEM. It was observed that the acid groups predominate on the surface of the three biosorbents. The process was optimized for all biosorbents at pH = 8, 7.5 g/L, 240 min, C0 = 250 mg/L, and 45 ℃. BT was more efficient in removing MB (96.20%; QMax = 35.71 mg/g), while IT and AT removed around 60% in similar conditions. The adsorption process best fits Langmuir and Redlich-Peterson isotherms, indicating a hybrid adsorption process (monolayer and multilayer) and pseudo-second-order kinetics. Thermodynamic data confirmed an endothermic and spontaneous adsorption process, mainly for BT. MB was also recovered through a desorption process with ethanol, allowing the BT recycling and reapplication of the dye. Thus, an efficient and sustainable biosorbent was developed, contributing to reducing environmental impacts.

An integrated assessment to reconstruct the history of changes influenced by multiple anthropogenic activities (City of Fortaleza, Ceará, Brazil).

In this study, the multi-marker approach was used for the first time with a highly urbanized lake located in the city of Fortaleza, Brazil, to provide a comprehensive view of temporal trends in sources of pollutants and evaluate the relation between the influence of anthropogenic activities and socioeconomic development. Total concentrations of the markers analyzed ranged from 21.0 to 103.8 ng g-1, 450.2 to 2390.2 ng g-1, and 233.8 to 9827.3 ng g-1 for ∑PAHs, ∑n-alk, and ∑sterols, respectively. Concentrations and patterns of PAH, AH, and sterol ratio distribution changed over time and may be associated with different episodes in the history of the city of Fortaleza. The marker ratio distribution in the sediment core revealed an overlap of natural and anthropogenic sources, with degraded oil, biogenic inputs, pyrogenic processes, and fecal contamination from humans and animals in the past changing to petroleum fossil inputs and high contamination from sewage in the present day. The distribution of markers and the chronological history of Fortaleza revealed two distinct periods related to human activities during the development of the city. In the first period (prior to the 1950s), the main human activities were animal breeding and the use of biomass for domestic activities, public and cargo transportation, and commercial activities, especially food production. In the second period (after the 1950s), expansion of the city occurred due to the so-called Brazilian economic miracle and the main human activities were industrialization and urbanization processes, involving deforestation, paving, sewage discharge, and petroleum combustion.

Pineapple (Ananás comosus) leaves ash as a solid base catalyst for biodiesel synthesis.

Homogeneous catalysts used for biodiesel synthesis have several limitations, including non-recoverability/reusability, saponification, emulsification, equipment corrosion, and environmental pollution. To overcome these limitations, we synthesized a novel catalyst via calcination of pineapple leaves waste. This catalyst was characterized by X-ray powder diffraction, X-ray fluorescence, Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and soluble alkalinity measurements. The catalyst's activity with regards to soybean oil transesterification was analyzed, and multiple process parameters (temperature, catalyst amount, reaction time, and methanol:oil molar ratio) were examined. A high catalytic activity, probably related to the 85 wt% content of alkali/alkali metals (K, Ca and Mg), was observed after a 30 min reaction time, 60 °C, 4 wt% of catalyst, oil to methanol molar ratio of 1:40, reaching an oil to biodiesel conversion above 98%. We conclude that the novel catalyst presented here is efficient, cost-effective, and sustainable, while simultaneously abundant waste is reduced.

Statistical mixture design investigation for extraction and quantitation of aporphine alkaloids from the leaves of Unonopsis duckei R.E. Fr. by HPLC-MS/MS.

INTRODUCTION: Alkaloids-derived drugs are a billionaire world-market and several phytochemical investigations aim the identification of new sources and/or structures. Thus, improving the way of extracting and methods to quantify them are of utmost importance. OBJECTIVE: To quantify isoquinoline-derived alkaloids in Unonopsis duckei R.E. Fr. through a new validated high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) method in combination with a statistical mixture design that aimed a proper direct extraction of these compounds from leaves. METHODOLOGY: Extracts were obtained with acetone, methanol, chloroform, and n-hexane in different combinations and proportions. Chemometrics were applied in order to compare peak areas, and therefore evaluate synergism and antagonism effects between the solvents. After selection of extraction solvent, the quantification was validated and applied in the best solvent combination to quantify the main alkaloids in U. duckei. RESULTS: Chemometrics indicated a synergistic effect between chloroform and methanol solvents, thus improving alkaloid extraction and extract yield. Analytes were quantified in a 15-min method, with limits of detection (LODs) between 0.5 and 5.2 ng/mL and limits of quantification (LOQs) between 1.6 and 17.2 ng/mL. The accuracy ranged between 80 and 120%. Coefficients of variation were lower than 17.42% at all concentrations. Concentrations of the alkaloids in U. duckei varied from 6.79 to 131.10 µg/g of dried leaf and glaziovine was found to be the main compound. CONCLUSION: The integration of simplex centroid model and quantification by HPLC-MS/MS is promising. Statistical optimisation of the alkaloid extraction and application of selective, sensitive and robust HPLC-MS/MS method will contribute to quality control applications in phytotherapeutic medicines.